mapbox GL JS - pass source data to custom layer

Question

I've added some quads with custom shaders to map (Examples are here and here). I need to pass data from my source to shader. Tutorials says that I can just pass 'source': 'point', to layer class constructor. Is it possible to pass source data to custom layer?

Here is source example:

map.addSource('point', {
    'type': 'geojson',
    'data': {
        'type': 'FeatureCollection',
        'features': [
            {
                'type': 'Feature',
                'geometry': {
                    'type': 'Point',
                    'coordinates': [0, 0]
                            }
            }
                    ]
              }
    });